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COVID-19 Alaska Clinical Update
Tuesday, February 23, 2021
Alaska cases & vaccinations
Virus transmission continues to decline since its peak in early December. As of February 22, 142,531 Alaskans (nearly 20% of the population) have received at least one dose of vaccine and 87,332 Alaskans have received both doses of vaccine.
ECHOs are still happening
A series of Q&A sessions via Zoom with clinicians and others involved in pandemic response happen weekly on a variety of topics. Clinicians may want to join for the COVID-19 Situational Awareness update Thursdays at noon, which overviews current literature, and the Alaska Healthcare ECHO held every other Tuesday evening at 7PM. The next Healthcare ECHO will be on March 2 and will include a discussion of adenovirus vectored vaccine technology and the Johnson and Johnson vaccine.
COVID-19 news
- A preprint, not yet peer-reviewed article from Harvard reported nasopharyngeal viral concentration over time in 65 patients with SARS-CoV-2, including 7 with the B.1.1.7 variant, found that the mean duration of PCR-detected infection with B.1.1.7 was 13.3 days with a proliferation period (time from first detectable virus to peak viral concentration) of 5.3 days, compared with 8.2 days and 2.0 days for non-B.1.1.7 virus respectively. They found similar peak viral concentrations with each strain. Authors note that extended duration of infection may contribute to increased transmissibility.
- Several articles have attempted to explain the low COVID-19 incidence in Africa, particularly outside of South Africa, with theories from recent experience with other epidemics to differences in demographics and chronic disease risk factors proposed. A postmortem surveillance survey of all decedents at a large hospital’s morgue in Lusaka, Zambia during June – September, 2020 found that 19% of decedents were positive for SARS-CoV-2. Of these, only 9% had been tested before death. Authors propose that the low reported COVID-19 incidence in many parts of Africa may be primarily due to undertesting.
- Two MMWRs on variants of concern: the average daily cases in Zambia increased 16-fold in one month after B.1.351 was detected, supporting increased transmissibility leading to increases in cases, hospitalizations and deaths. Another describes Minnesota’s detection of 8 cases with B.1.1.7, six of whom had recently traveled (although none to the UK).
- A randomized clinical trial (n=240) of high dose vitamin D3 in hospitalized patients with COVID-19 found no benefit despite an appropriate dose response in 25(OH)D level; JAMA published commentary as well.
- The SOFA score performed poorly in predicting mortality prior to intubation for COVID-19 pneumonia. Authors note that age alone performed significantly better as a predictive factor for mortality.
- A small study of antibody tests found that sensitivity varied widely by test type, with one maximum sensitivity of 0.67, and sensitivity lower in females and patients younger than 40 or older than 59. Additionally, measuring serologic levels soon after SARS-CoV-2 infection reduced detection and antibody response varied significantly with timing of sample; sensitivity was especially poor in the first 1-2 months after infection. CDC notes antibody tests cannot indicate with certainty the presence or absence of current or previous SARS-CoV-2 infection and recommends against using them to determine immune status. The FDA recently published their experience with SARS-CoV-2 serology tests, noting that the policy early in the pandemic of requiring antibody test manufacturers to notify the FDA but not obtain an emergency use authorization resulted in a market flooded with poorly performing tests with misleading marketing.
Vaccine news
- CDC released a MMWR on the first month of safety data since the mRNA vaccines received emergency use authorization, noting that local and systemic reactions were common, rare reports of anaphylaxis (4.5 per million doses) were received and no unusual or unexpected reporting patterns were detected.
- CDC is hosting an informational Zoom meeting for clinicians to get an overview of the Johnson & Johnson/Janssen vaccine at 10AM Alaska time on March 2nd. It will also be recorded for viewing later at the same website. Clinicians will learn about vaccine characteristics and administration, vaccinating special populations, and contraindications. CDC will also answer a number of clinical questions they have received about this new vaccine.
- Two preprint, not yet peer-reviewed studies suggest the Pfizer mRNA vaccination may reduce transmission. In one, individuals who were at least two weeks from their first dose when testing positive for SARS-CoV-2 likely had viral loads 1.6x to 20x lower than unvaccinated individuals. Another study found viral load reduced 4-fold in infections occurring 12-28 days after the first dose of vaccine.
- Serology studies after vaccination found similar neutralizing activity against B.1.1.7 variant samples but somewhat diminished against B.1.351 for Moderna’s vaccine; a similar trial showed somewhat diminished efficacy against B.1.351 with Pfizer’s vaccine. The significance of these small studies in terms of vaccine protection against the variants is not yet known. CDC published further commentary in JAMA calling for increased mitigation measures, increased genomic surveillance, and accelerating vaccination to remain ahead of variants.
- The first SARS-CoV-2 human challenge trial to characterize the smallest amount of virus needed to cause infection has been approved in the UK. Future stages will include patients vaccinated prior to exposure to assess vaccine efficacy.
- The AstraZeneca vaccine is starting a Phase 2 clinical trial in children aged 6-17.
- Moderna is also conducting a Phase 2/3 clinical trial in 3,000 children aged 12-17.
- Pfizer announced a global Phase 2/3 trial in 4,000 pregnant women between 24 and 34 weeks of gestation. It will evaluate safety and immunogenicity in women and safety as well as transfer of potentially protective antibody to infants.
Vaccine status
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